Process of tanning hides or skins of animals



No. 6I4,929. Patented Nov. 29, |898.

` G. D. BURTON.

PROCESS 0F TANNING HIDES 0R SKINS 0F ANIMALS.

(Application med Apr. 5, 189s.)

Irl

WITNEEEEE VEN-VDR No.v 6I4,929. Patented Nov. 29, |898.

G. D. BURTON.

PBUCESS 0F TANNING HIDES 0R SKINS 0F ANIMALS.

(Application med Apr. 5. 189s.) (No Model.) 2 Sheets-Sheet 2.

VVWNEESEEA v rent of electricity is passed.

UNITED STATES PATENT EEicE.

GEORGE D. BURTON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE UNITED STATES ELECTRICAL LEATHER PROCESS COMPANY, OF

MAINE.

PROCESS OF TANNING HIDES OR SKINS OF ANIMALS.

SPECIFICATION forming part of Letters Fatent No. 614,929, dated November 29, 1898.

Application iiled April 5, 1898.

To all whom it may concern,.-

Be it known that I, GEORGE D. BURTON, a citizen of the United States of America, residing at Boston, in the county of Suffolk, in the State of Massachusettshave invented certain new and useful Improvements in Processes of Tanning and Coloring Animal Hides or Skins Electrically, of Which the following is a specification.

This invention relates to tanning and coloring animal hides and skins by subjecting them to the action of a tanning and coloring solution and to a current of electricity passed therethrough.

The object of this invention is to effect a rapid tanning and coloring of animal hides or skins.

In carrying out the process the hides and skins are subjected to the action of a tanning and coloring solution through which a cur- In some cases the hides or skins are subjected at once to the action of a solution containing both tanning and coloring materials, a current of electricity being passed through said solution. In other cases the hides and skins are iirst subjected to the action of a tanning solution through j which a current of electricity is passed. Then coloring-matter is added to said tanning solution,and the electric current is again passed through the solution having the added colorin g-matter, whereby the skins are tanned and colored Without removal from the solution.

Figure l of the accompanying drawings is a View of an apparatus for carrying out this process, comprising an electric generator, a switch-table, and a tank for containing the tanning and coloring solution through which the electricity is passed, the generator and table being shown in side elevation and the tank in longitudinal vertical section. Fig. 2 represents a plan View of the apparatus.l Fig. 3 represents a vertical transverse section thereof.

The same reference-letters indicate corresponding parts in all the figures.

The apparatus herein shown for carrying out the process comprises a tank A for containing the tanning and coloring solution B.

This tank is preferably composed of or lined Serial No. 676,603. (N0 specimens.)

with a non-conducting substance. Two electrodes D D are disposed in the tank,preferably atopposite ends thereof. These electrodes are composed of any suitable material, prefably of a material which will not dissolve in or be acted upon by the solution. To this end they are preferably composed of carbon composition of a considerable density. I have used for this purpose a dense commercial carbon. These electrodes are connected by conductors H H With a switch F for controlling the electric current. The switch is connected by conductors .I J With a dynamo G or other generator of electricity.

Screens C C, composed of Wood or other non-conducting material, are disposed in the tank to prevent the hides or skins from coming in contact With the electrodes D D. A screen E, also composed of Wood or other non-conducting material, is supported in the tank near the bottom thereof. This screen prevents the skins or hides from coming into direct contact with the bottom of the tank and permits the tanning and coloring liquid to circulate underneath the skins or hides.

Means are provided for agitating or keeping in circulation the solution Within the tank. The means herein shown for this purpose comprises a shaft P, which extends through the tank and projects through one side thereof. This shaft is provided with Wings or stirrers a. IVhere the shaft passes through the side of the tank it is provided With a stuffing-box N to prevent leakage. This shaft is provided at its outer end with a pulley M, over which a belt L runs to a pulley K on the shaft of the dynamo. The circulation of the liquid prevents the tanning or coloring material from settling in the tank and causes an even distribution of said material throughout the tank, whereby a morev rapid action of the solution on the skins or hides is obtained.

Any suitable source of electricity may be ,f

used. A As an example of one way of carrying out the process I will state that a solution is formed in thetank composed of, say, seventy gallons of Water, two quarts of tannc acid or extract of chestnut, oak, or hemlock bark,

IOO

together with four ounces of chlorid of sodium. The bath is then stirred briskly for a few minutes, so that the ingredients are thoroughly dissolved or mixed. This solution will have a specific gravity of, say, 1.030 at an ordinary temperature, say, 63o Fahrenheit. I then place in the bath or solution, say, four dozen skins to be tanned, or one dozen hides,which have been previously properly prepared for tanning. comprise goat-skins, kangaroo-skins, calfskins, or ox or cow hides. A current of electricity is then passed through the solution. The chlorid of sodium increases the density of the solution and facilitates the electric action. Any other suitable material may be used for this purpose. The material to be tanned and colored is subjected to the action of the bath for a su Fticient period, say, in the case of skins from two to four hours and in case of hides from six to eight hours. The electric current is passed through the bath or solution containing the hides or skins during a portion or the whole period of treatment. Then a suitable coloring material is added to the solution. This coloring material may, for example, consist of crystallized extract of logwood, sulfite of iron, and sulite of copperin the proportions, say, two pounds of crystallized extract of logwood, threequarters of a pound of sullite of iron, and one-half pound of suliite of copper. The solution is then stirred or agitated to cause a mixture of the coloring-matter with the solution, and then the electric current is again passed through the solution. The hides or skins remain in the solution containing the coloring-matter until they are sufficiently colored.

I may also add to the above solution, as a modification of the coloring solution, two ounces of iodide of potassium and one-half a pound of bichromate of potassium, which will change the color from a purple to a black.

A current of from twenty to iive hundred volts and from ten to one hundred amperes is used, according to the size of the tank, the gravity of the solution, and the number of skins or hides to be tanned.

Instead of iirst subjecting the hides or skins to the tanning solution and the electric current and then adding the coloring material and subjecting them to the same solution and an electric current plus the coloring-matter I may add the coloring material directly to the tanning solution in the first instance.

These skins may A combined tanning and coloring solution may be composed of two quarts of tannic acid, two ounces of bichromate of potassium dissolved in, say, seventy gallons of water, and a coloring-matter consisting of threequarters of a pound of sulite of iron and onehalf pound of sulte of copper. This will give a black color to the leather. j

The passing of an electric current of a sutlicient volume and pressure through the solution tends to open the pores and permit the tanning and coloring liquid to more rapidly enter or penetrate them.

Different coloring and different tanning materials may be used without departing from j the scope of this invention.

Claim 2 at the end of this speciication is to be construed as covering the process set forth therein, whether the solution be subjected to mechanical agitation during the whole or only during a part of the time required to perform the tanning and coloring operation.

I claim as my inventionl. The process of tanning and coloring hides or skins which consists in placing the hides or skins in a tanning solution, passing an electric current through said solution containing the hides or skins, then adding coloring-matter to said solution, and again passing the electric current therethrough.

2. The process of tanning and coloring hides or skins, which consists in placing the hides or skins in a tanning solution, passing an electric current through said solution containing said hides or skins, then adding coloring-matter to said solution, again passing the electric current therethrough, and subjecting said solution to mechanical agitation during the tanning and coloring operation.

3/The process of tanning hides or skins which consists in subjecting the hides or skins to the action of a solution containing tanning material, extraneous coloring-matter and a dissolved solvent which adds density and conductivity to the solution, and passing an electric current through said solution in which the hides or skins are placed.

In testimony that I claim the invention above set forth I affix my signature in presence of two witnesses.

GEO. D. BURTON.

Witnesses:

E. F. PHILIrsoN, Guo. STEINE.

Correction in Letters Patent No. 614,929.

It is hereby certified that in Letters Patent No. 614,929, granted November 29, 1898,

upon the application of George D. Burton, of Boston, Massachusetts, for an improvement in Processes of Tanning Hides or Skins of Animals,77 an error appears in the `printed specificationv requiring correction, as follows: In line 101, page 2, the Word solvent should read sot/vend; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the oase in the Patent Oiioe.

Signed, eountersigned, and sealed this 13th day of December, A. D., 1898.

[SEAL] WEBSTER DAVIS,

Assistmtt Secretary of the Interior. Gountersigned C. H. DUELL,

Commissioner of Patents. 

